Question

A theater has 20 rows of chairs. The first row has 16 chairs, the second has 18, the third has 20, and so on. In total, the theater seats _____ people.

Answer 1

if all the rows had 16 chairs there would be 20*16

Answer 2

the extra seats are 2+4+...+ 38= 2(1+2+3...+19)

Answer 3

sum of numbers 1+2+..+n = n(n+1)/2

Answer 4

what is the answer

Answer 5

do you know how to add?

Answer 6

what is the answer

Answer 7

what is the answer

Answer 8

700